A technology disclosed herein relates to a storage subsystem management method and, more particularly, to a method of reducing power consumption in NAS.
NAS stands for network attached storage, a known technology in which a storage system connected to a network is used as a shared disk by multiple client computers connected to the network. NAS is composed of a server which contains a network interface and the like, and a disk device which stores data. A server constituting NAS is called a NAS server or a NAS node (hereinafter, simply referred to as node).
The amount of power consumed by NAS in providing a file-sharing service is increasing. This results from the recent advance in computer performance and node duplication for redundancy which ensures the continuity of the service. There is a known technology for avoiding an increase in power consumption due to redundancy, which is called cold standby (see, for example, JP 2005-267111 A). Cold standby shuts down a standby node, and thus prevents power consumption from increasing in proportion to the number of nodes introduced.
Meanwhile, a technology for controlling computer power is also known. For example, an advanced configuration and power interface (ACPI) is a standard defined for enabling an operating system (OS) to manage the power of each component of a computer in cooperation with a basic input/output system (BIOS) (see Hewlett-Packard Corporation and four others, “Advanced Configuration and Power Interface Specification Revision 3.0b”, retrieved from the Internet on Jul. 5, 2007 at http://www.acpi.info/DOWNLOADS/ACPIspec30b.pdf) online, Oct. 10, 2006. ACPI allows an OS to finely set and manage the power control function of each component.